[Mesa-dev] [PATCH 2/3] nv20: Fix GL_CLAMP

[Ian Romanick]

On 07/13/2017 06:50 PM, Ilia Mirkin wrote:
> According to rnndb, GL_CLAMP with value 0x5 is actually supported on
> nv10+. I'd name the function *_nv10.
> 
> I have, at various times, tried to solve some issues by using the 0x5
> clamp on my nv1x hardware (nv17 and nv18), with no positive effect.
> This is a piglit run I have around from some time back:
> 
> https://people.freedesktop.org/~imirkin/nv10-comparison/problems.html
> 
> in case you're curious. I guess this is consistent with your results -
> no change from doing this, until we get to borders.

I saw that in rnndb.  This is partially what fuels my suspicion that
GL_CLAMP on NV10 clamps with the 1-texel border.  Since this driver
doesn't provide a border, it doesn't blend with anything.

One of these days I'll figure out how to probe the closed driver to see
what it does.  The last driver that supports NV10 only works on Fedora 6
or similarly old.  That... will require quite some motivation.

> With or without that function name change, this is
> 
> Reviewed-by: Ilia Mirkin <imirkin at alum.mit.edu>
> 
> [apologies this took me a while to get to]
> 
> On Tue, Jun 27, 2017 at 1:09 PM, Ian Romanick <idr at freedesktop.org> wrote:
>> From: Ian Romanick <ian.d.romanick at intel.com>
>>
>> v2: Force T and R wrap modes to GL_CLAMP_TO_EDGE for 1D textures.
>> This fixes a regression in tex1d-2dborder.  The test uses a 1D texture
>> but it provides S and T texture coordinates.  Since the T wrap mode
>> would (correctly) be set to GL_CLAMP, the texture would gradually
>> blend (incorrectly) with the border color.
>>
>> I also tried setting NV20_3D_TEX_FORMAT_DIMS_1D instead of
>> NV20_3D_TEX_FORMAT_DIMS_2D for 1D textures, but that did not help.
>>
>> It is possible that the same problem exists for 2D textures with the
>> R-wrap mode, but I don't think there are any piglit tests for that.
>>
>> No test changes on NV20 (10de:0201).
>>
>> Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
>> ---
>>  src/mesa/drivers/dri/nouveau/nouveau_gldefs.h | 19 +++++++++++++++++++
>>  src/mesa/drivers/dri/nouveau/nv20_state_tex.c | 16 +++++++++++++---
>>  2 files changed, 32 insertions(+), 3 deletions(-)
>>
>> diff --git a/src/mesa/drivers/dri/nouveau/nouveau_gldefs.h b/src/mesa/drivers/dri/nouveau/nouveau_gldefs.h
>> index 46ec14e..7df04c1 100644
>> --- a/src/mesa/drivers/dri/nouveau/nouveau_gldefs.h
>> +++ b/src/mesa/drivers/dri/nouveau/nouveau_gldefs.h
>> @@ -239,6 +239,25 @@ nvgl_wrap_mode(unsigned wrap)
>>  }
>>
>>  static inline unsigned
>> +nvgl_wrap_mode_nv20(unsigned wrap)
>> +{
>> +       switch (wrap) {
>> +       case GL_REPEAT:
>> +               return 0x1;
>> +       case GL_MIRRORED_REPEAT:
>> +               return 0x2;
>> +       case GL_CLAMP:
>> +               return 0x5;
>> +       case GL_CLAMP_TO_EDGE:
>> +               return 0x3;
>> +       case GL_CLAMP_TO_BORDER:
>> +               return 0x4;
>> +       default:
>> +               unreachable("Bad GL texture wrap mode");
>> +       }
>> +}
>> +
>> +static inline unsigned
>>  nvgl_filter_mode(unsigned filter)
>>  {
>>         switch (filter) {
>> diff --git a/src/mesa/drivers/dri/nouveau/nv20_state_tex.c b/src/mesa/drivers/dri/nouveau/nv20_state_tex.c
>> index b0a4c9f..7972069 100644
>> --- a/src/mesa/drivers/dri/nouveau/nv20_state_tex.c
>> +++ b/src/mesa/drivers/dri/nouveau/nv20_state_tex.c
>> @@ -193,9 +193,19 @@ nv20_emit_tex_obj(struct gl_context *ctx, int emit)
>>                 | NV20_3D_TEX_FORMAT_NO_BORDER
>>                 | 1 << 16;
>>
>> -       tx_wrap = nvgl_wrap_mode(sa->WrapR) << 16
>> -               | nvgl_wrap_mode(sa->WrapT) << 8
>> -               | nvgl_wrap_mode(sa->WrapS) << 0;
>> +       switch (t->Target) {
>> +       case GL_TEXTURE_1D:
>> +               tx_wrap = NV20_3D_TEX_WRAP_R_CLAMP_TO_EDGE
>> +                       | NV20_3D_TEX_WRAP_T_CLAMP_TO_EDGE
>> +                       | nvgl_wrap_mode_nv20(sa->WrapS) << 0;
>> +               break;
>> +
>> +       default:
>> +               tx_wrap = nvgl_wrap_mode_nv20(sa->WrapR) << 16
>> +                       | nvgl_wrap_mode_nv20(sa->WrapT) << 8
>> +                       | nvgl_wrap_mode_nv20(sa->WrapS) << 0;
>> +               break;
>> +       }
>>
>>         tx_filter = nvgl_filter_mode(sa->MagFilter) << 24
>>                 | nvgl_filter_mode(sa->MinFilter) << 16
>> --
>> 2.9.4
>>
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